I've watched every single play of this season on the All-22 and can definitively say that guys get open.
These wide receivers and tight ends might not have that crazy DeAndre Hopkins/Odell Beckham/Antonio Brown catch radius (aka the ability to make catches on not perfectly thrown balls), but they get enough separation to be more effective than this offense has been.
Obviously Antonio Brown has proven his metrics wrong, but coming into the league his catch radius was a pretty godawful 18th percentile. His only above average metric was his agility, and even that was only 55th percentile. Just goes to show that sometimes guys drastically overachieve their profile, just like a lot of guys drastically underachieve it. Certainly hasn't hurt that he's had a top ten QB throwing to him for basically his entire career, obviously. He's been a lot less effective when Ben has missed games, though, so that certainly plays a factor. Regardless, Brown certainly wasn't a "can't miss" prospect coming into the league. There's a reason he was drafted in the sixth round, and it wasn't because every team was incompetent.
Hopkins was only 50th percentile catch radius, by the way, although he obviously benefits from being a bigger target with a 63rd percentile height-adjusted speed score. Hopkins also had a breakout age of 18.2, which is 99th percentile, which tends to signify that he was a special player.
Beckham, on the other hand, actually did profile out to have an elite catch radius. He was 95th percentile, and also had fantastic agility, speed, and burst.
Worth noting that Coleman has a 92nd percentile catch radius and 94th percentile burst. He doesn't have an agility score listed on the site I'm using, but I'd imagine it's above the 50th percentile, because all his other metrics are.